gitea: default repo setting; editor: asset picker with thumbnail grid

Gitea plugin: default_repo field per account (stored in DB, pre-fills
create issue form but stays editable). Editor toolbar: asset picker
flyout with 4-column thumbnail grid and live search filter. Clicking
a tile inserts the matching markdown.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

config.php

@@ -1,7 +1,7 @@
 <?php
 
 define('APP_NAME', 'hyprcrd');
-define('APP_VERSION', '1.1.0');
+define('APP_VERSION', '1.2.0');
 
 // Database path — writable directory, outside webroot
 // DB_PATH / UPLOAD_DIR can be pre-defined by the Electron router for app isolation